scholarly journals Exosomal Transfer of MiR-500a-3p Confers Cisplatin Resistance and Stemness via Targeting FBXW7 in Gastric Cancer

2020 ◽  
Author(s):  
Hao Lin ◽  
Caihua Zhang ◽  
Liang Zhang ◽  
pengpeng liu
Keyword(s):  
Gastric Cancer ◽  
Cisplatin Resistance ◽  
Luciferase Reporter ◽  
In Vivo Experiments ◽  
Bioinformatics Software ◽  
Alternative Modality ◽  
Cisplatin Sensitivity

Abstract Background Chemoresistance has become a major obstacle for gastric cancer (GC) therapy in clinical practice. MiRNAs have been reported to play critical roles in the development of chemoresistance in various tumors, including GC. However, the role of MiR-500a-3p within exosomes in cisplatin-resistant GC cells remains largely unknown. Materials and methods Cell proliferation and exosome delivery assays were performed using CCK-8 and transwell assays, respectively. CD63, CD81, β-tubulin, FBXW7, GAPDH, CD133, CD44 and SOX2 were detected by western blot and immunofluorescence assays. The expression levels of miR-500a-3p and FBXW7 mRNA were measured by real-time qRT-PCR. The interaction between miR-500a-3p and FBXW7 was predicted by bioinformatics software and confirmed by the dual-luciferase reporter. The mechanism of exosomal miR-500a-3p for cisplatin resistance was investigated in vitro and in vivo experiments. Results MiR-500a-3p level was upregulated in cisplatin-resistant GC cells and its downregulation enhanced cisplatin sensitivity. Moreover, extracellular miR-500a-3p could be incorporated into exosomes and transmitted to sensitive cells, thus disseminating cisplatin resistance. Additionally, exosomal miR-500a-3p promoted cisplatin resistance via targeting FBXW7 in vitro and in vivo . Clinically, higher expression of miR-500a-3p in the plasma exosomes of GC patients is correlated with DDP resistance and thereby results in poor progression-free prognosis. Conclusion Our finding highlights the potential of exosomal miR-500a-3p as an alternative modality for the prediction and treatment of GC with chemoresistance, providing a novel avenue for the treatment of GC.

scholarly journals Functional Role of the SLC7A11-AS1/xCT Axis in the Development of Gastric Cancer Cisplatin-resistance by a GSH-dependent Mechanism

2021 ◽  
Author(s):  
Yajun Luo ◽  
Wanping Xiang ◽  
Zilin Liu ◽  
Lin Yao ◽  
Linghan Tang ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Cisplatin Resistance ◽  
Poor Response ◽  
Functional Roles ◽  
In Vivo Experiments ◽  
Platinum Based Chemotherapy ◽  
Response To Chemotherapy

Abstract Background: Resistance to platinum-based chemotherapy is a major obstacle in gastric cancer (GC) treatment. Abundant long noncoding RNAs (lncRNAs) are reported to play important roles in tumorigenesis and drug resistance biology. We aimed to investigate the roles and mechanisms of SLC7A11-AS1 in GC cisplatin resistance.Methods: Quantitative real-time PCR (qRT-PCR), RNA fluorescence in situ hybridization (RNA-FISH), immunofluorescence staining and immunohistochemistry were performed on GC tissues or cells to assess expression of SLC7A11-AS1/xCT axis. Cell migration, invasion and apoptosis ability were evaluated by wound healing, transwell and flow cytometry assays. The functional roles of SLC7A11-AS1/xCT axis in GC cisplatin resistance were demonstrated by a series of in-vitro and in-vivo experiments.Results: We report that the SLC7A11-AS1 and xCT are involved in cisplatin resistance in GC. SLC7A11-AS1 was downregulated and xCT was upregulated in cisplatin-resistant GC tissues and cell lines. GC patients with low expression of SLC7A11-AS1 and high expression of xCT had a poor prognosis and relatively poor response to chemotherapy. Overexpression of SLC7A11-AS1 weakened GC growth, reduced intracellular GSH biosynthesis, enhanced intracellular reactive oxygen species (ROS) and conferred sensitivity to cisplatin to resistant GC cells in vitro and in vivo. Mechanistically, SLC7A11-AS1 directly suppressed xCT expression, while miR-33a-5p remarkably reduced SLC7A11-AS1 and xCT expression by directly targeting the SLC7A11-AS1 and xCT 3’UTRs. In addition, we found that low SLC7A11-AS1 expression activated the p38MAPK-JNK signaling pathway, and increased the expression of cisplatin export gene ATP7A and the GSH biosynthesis gene GCLM in GC. Conclusions: These findings suggest that the SLC7A11-AS1/xCT axis is a crucial therapeutic target to overcome platinum-related resistance for GC treatment.

scholarly journals Has-miR-875-5p Inhibits Tumorigenesis by Targeting USF2 via TGF-β Signaling Pathway in Gastric Cancer

2021 ◽  
Author(s):  
Shenshuo Gao ◽  
Zhikai Zhang ◽  
Xubin Wang ◽  
Yan Ma ◽  
Chensheng Li ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Signaling Pathway ◽  
Research Direction ◽  
Luciferase Reporter ◽  
Migration And Invasion ◽  
Gastric Cancer Cells ◽  
New Research

Abstract Background: Gastric cancer (GC) is one of the most common malignancies, and more and more evdiences show that the pathogenesis is regulated by various miRNAs.In this study, we investigated the role of miR-875 in GC. Methods:The expression of miR-875-5p was detected in human GC specimens and cell lines by miRNA RT-PCR. The effect of miR-875-5p on GC proliferation was determined by CCK-8 proliferation assay and EDU assay. Migration and invasion were examined by transwell migration and invasion assay and wound healing assay. The interaction between miR-875-5p and its target gene USF2 was verified by a dual luciferase reporter assay. The effects of miR-875-5p in vivo were studied in xenograft nude mice models.Related proteins were detected by Western blot.Results:The results showed that miR-875-5p inhibited the proliferation, migration and invasion of gastric cancer cells in vitro, and inhibited tumorigenesis in vivo. USF2 proved to be a direct target of miR-875-5p. Knockdown of USF2 partially counteracts the effects of miR-875-5p inhibitors.Overexpression of miR-875-5p can inhibit proliferation, migration, and invasion through the TGF-β signaling pathway by down-regulation of USF2 in GC, providing a new research direction for the diagnosis and targeted therapy of GC.Conclusions: MiR-875-5pcan inhibited the progression of GC by directly targeting USF2 and negatively regulating TGF-β signaling pathway.In the future, miR-875-5p is expected to be used as a potential therapeutic target for GC therapy.

scholarly journals CircRNA-DOPEY2 enhances the chemosensitivity of esophageal cancer cells by inhibiting CPEB4-mediated Mcl-1 translation

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Zhenchuan Liu ◽  
Shaorui Gu ◽  
Kaiqin Wu ◽  
Lei Li ◽  
Chenglai Dong ◽  
...  
Keyword(s):  
Cancer Progression ◽  
Cisplatin Resistance ◽  
Critical Role ◽  
Circular Rnas ◽  
Major Barrier ◽  
Downstream Target ◽  
Cisplatin Sensitivity

Abstract Background Cisplatin-based chemotherapy is a mainstay systematic therapy for advanced esophageal squamous cell carcinoma (ESCC), and cisplatin resistance, which is not uncommon, is the major barrier to improving patient outcomes. Circular RNAs (circRNAs) are novel noncoding RNAs that are implicated in cancer progression, but their involvement in modulating cisplatin responsiveness in ESCC remains unknown. Methods Bioinformatics analysis was used to profile and identify the circRNAs involved in cisplatin responsiveness in ESCC. The chemosensitive role of cDOPEY2 was confirmed both in vitro and in vivo. The molecular mechanism of cDOPEY2 was investigated by mass spectrometry, immunoprecipitation, and ubiquitination analyses. Results We report that a novel circRNA (cDOPYE2, hsa_circ_0008078) was markedly downregulated in cisplatin-resistant ESCC cells (ESCC-CR) compared with parental chemosensitive cells. Re-expression of cDOPEY2 substantially enhanced the cell-killing ability of cisplatin by augmenting the apoptotic process in ESCC-CR cells, which was achieved by decreasing the abundance of the antiapoptotic protein Mcl-1. Mechanistically, we showed that cDOPEY2 acted as a protein scaffold to enhance the interaction between the cytoplasmic polyadenylation element binding protein (CPEB4) and the E3 ligase TRIM25, which in turn facilitated the ubiquitination and degradation of CPEB4. The increased Mcl-1 expression in ESCC-CR cells was dependent on the binding of CPEB4 to its untranslated mRNA, and depletion of CPEB4 mediated by cDOPEY2 reversed this effect. Rescue experiments confirmed that the critical role of cDOPEY2 in maintaining cisplatin sensitivity was dependent on the depletion of CEPB4 and its downstream target Mcl-1. Clinical and in vivo data further corroborated the significant relevance of cDOPEY2 to cisplatin responsiveness in ESCC. Conclusions We provide evidence that cDOPEY2 inhibits CPEB4-mediated Mcl-1 translation by promoting the ubiquitination and degradation of CPEB4 to alleviate cisplatin resistance, indicating that cDOPEY2 may serve as a valuable biomarker and potential therapeutic target in ESCC.

scholarly journals METTL3-mediated N6-methyladenosine modification is critical for epithelial-mesenchymal transition and metastasis of gastric cancer

2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Ben Yue ◽  
Chenlong Song ◽  
Linxi Yang ◽  
Ran Cui ◽  
Xingwang Cheng ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Epithelial Mesenchymal Transition ◽  
Luciferase Reporter ◽  
Mesenchymal Transition ◽  
Qrt Pcr ◽  
Rna Immunoprecipitation ◽  
E Cadherin

Abstract Background As one of the most frequent chemical modifications in eukaryotic mRNAs, N6-methyladenosine (m6A) modification exerts important effects on mRNA stability, splicing, and translation. Recently, the regulatory role of m6A in tumorigenesis has been increasingly recognized. However, dysregulation of m6A and its functions in tumor epithelial-mesenchymal transition (EMT) and metastasis remain obscure. Methods qRT-PCR and immunohistochemistry were used to evaluate the expression of methyltransferase-like 3 (METTL3) in gastric cancer (GC). The effects of METTL3 on GC metastasis were investigated through in vitro and in vivo assays. The mechanism of METTL3 action was explored through transcriptome-sequencing, m6A-sequencing, m6A methylated RNA immunoprecipitation quantitative reverse transcription polymerase chain reaction (MeRIP qRT-PCR), confocal immunofluorescent assay, luciferase reporter assay, co-immunoprecipitation, RNA immunoprecipitation and chromatin immunoprecipitation assay. Results Here, we show that METTL3, a major RNA N6-adenosine methyltransferase, was upregulated in GC. Clinically, elevated METTL3 level was predictive of poor prognosis. Functionally, we found that METTL3 was required for the EMT process in vitro and for metastasis in vivo. Mechanistically, we unveiled the METTL3-mediated m6A modification profile in GC cells for the first time and identified zinc finger MYM-type containing 1 (ZMYM1) as a bona fide m6A target of METTL3. The m6A modification of ZMYM1 mRNA by METTL3 enhanced its stability relying on the “reader” protein HuR (also known as ELAVL1) dependent pathway. In addition, ZMYM1 bound to and mediated the repression of E-cadherin promoter by recruiting the CtBP/LSD1/CoREST complex, thus facilitating the EMT program and metastasis. Conclusions Collectively, our findings indicate the critical role of m6A modification in GC and uncover METTL3/ZMYM1/E-cadherin signaling as a potential therapeutic target in anti-metastatic strategy against GC.

scholarly journals Low GAS5 expression may predict poor survival and cisplatin resistance in cervical cancer

2020 ◽  
Vol 11 (7) ◽  
Author(s):  
Xingyu Fang ◽  
Guanglei Zhong ◽  
Yuhan Wang ◽  
Zhongqiu Lin ◽  
Rongchun Lin ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
Animal Studies ◽  
Cisplatin Resistance ◽  
Suppressor Gene ◽  
Tumour Suppressor Gene ◽  
Luciferase Reporter ◽  
Poor Overall Survival ◽  
Cisplatin Sensitivity

Abstract Cisplatin resistance is a major challenge in cervical cancer (CC) chemotherapy. Growth arrest‐specific 5 (GAS5) has been reported to be a tumour suppressor gene in CC. However, the mechanism of GAS5 in chemoresistance remains undetermined. Our research evaluated GAS5 expression in normal and CC tissues by qPCR and in situ hybridization (ISH). Statistical analysis was conducted to analyse the association of GAS5 expression with survival. Biochemical methods were used to screen upstream and downstream regulators of GAS5. Then, interactions were confirmed by ChIP, RNA pull-down, RNA immunoprecipitation (RIP), dual-luciferase reporter and real-time PCR assays. The cisplatin sensitivity of GAS5-overexpressing CC cells was demonstrated in vitro and in vivo. The results showed that low GAS5 expression was correlated with poor overall survival. Mechanistically, GAS5 was transcriptionally modulated by P-STAT3 and served as a competing endogenous RNA (ceRNA) of miR-21 to indirectly affect cisplatin sensitivity through PDCD4 regulation in CC cells. Animal studies confirmed that GAS5 enhanced cisplatin sensitivity and promoted PDCD4 expression in vivo. GAS5 was regulated by P-STAT3 and affected the sensitivity of CC to cisplatin-based chemotherapy through the miR-21/PDCD4 axis. This result may provide new insight into cisplatin-based therapy.

scholarly journals HOXA10 mediates epithelial-mesenchymal transition to promote gastric cancer metastasis partly via modulation of TGFB2/Smad/METTL3 signaling axis

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Chenlong Song ◽  
Chongzhi Zhou
Keyword(s):  
Gastric Cancer ◽  
Western Blot ◽  
Lung Metastasis ◽  
Essential Role ◽  
Luciferase Reporter ◽  
Migration And Invasion ◽  
Signaling Axis

Abstract Background Homeobox A10 (HOXA10) belongs to the HOX gene family, which plays an essential role in embryonic development and tumor progression. We previously demonstrated that HOXA10 was significantly upregulated in gastric cancer (GC) and promoted GC cell proliferation. This study was designed to investigate the role of HOXA10 in GC metastasis and explore the underlying mechanism. Methods Immunohistochemistry (IHC) was used to evaluate the expression of HOXA10 in GC. In vitro cell migration and invasion assays as well as in vivo mice metastatic models were utilized to investigate the effects of HOXA10 on GC metastasis. GSEA, western blot, qRT-PCR and confocal immunofluorescence experiments preliminarily analyzed the relationship between HOXA10 and EMT. ChIP-qPCR, dual-luciferase reporter (DLR), co-immunoprecipitation (CoIP), colorimetric m6A assay and mice lung metastasis rescue models were performed to explore the mechanism by which HOXA10 accelerated the EMT process in GC. Results In this study, we demonstrated HOXA10 was upregulated in GC patients and the difference was even more pronounced in patients with lymph node metastasis (LNM) than without. Functionally, HOXA10 promoted migration and invasion of GC cells in vitro and accelerated lung metastasis in vivo. EMT was an important mechanism responsible for HOXA10-involved metastasis. Mechanistically, we revealed HOXA10 enriched in the TGFB2 promoter region, promoted transcription, increased secretion, thus triggered the activation of TGFβ/Smad signaling with subsequent enhancement of Smad2/3 nuclear expression. Moreover, HOXA10 upregulation elevated m6A level and METTL3 expression in GC cells possible by regulating the TGFB2/Smad pathway. CoIP and ChIP-qPCR experiments demonstrated that Smad proteins played an important role in mediating METTL3 expression. Furthermore, we found HOXA10 and METTL3 were clinically relevant, and METTL3 was responsible for the HOXA10-mediated EMT process by performing rescue experiments with western blot and in vivo mice lung metastatic models. Conclusions Our findings indicated the essential role of the HOXA10/TGFB2/Smad/METTL3 signaling axis in GC progression and metastasis.

Exosomal miR-196a-1 promotes gastric cancer cell invasion and metastasis by targeting SFRP1

Nanomedicine ◽  
2019 ◽  
Vol 14 (19) ◽  
pp. 2579-2593 ◽  
Author(s):  
Chun Feng ◽  
Junjun She ◽  
Xiaobing Chen ◽  
Qunchao Zhang ◽  
Xu Zhang ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Expression Profiles ◽  
Mirna Microarray ◽  
In Vivo Experiments ◽  
Exosomal Mirnas ◽  
Mirna Expression Profiles ◽  
High Expression Level

Aim: To investigate the role of exosomal miRNAs on gastric cancer (GC) metastasis. Materials & methods: miRNA expression profiles of exosomes with distinct invasion potentials were analyzed using miRNA microarray and validated by quantitative real-time PCR. In vitro and in vivo experiments assessed the role of exosomal miR-196a-1 in GC's metastasis. Results: High expression level of exosomal miR-196a-1 expression was significantly associated with poor survival in GC. Exosomes that contained miR-196a-1 were secreted from high-invasive GC cells. Ectopic miR-196a-1 expression promoted invasion of low-invasive GC cells by targeting SFRP1. Conclusion: miR-196a-1 was delivered from high-invasive GC into low-invasive GC cells via exosomes and promoted metastasis to the liver in vitro and in vivo.

scholarly journals Silencing circSLAMF6 represses cell glycolysis, migration, and invasion by regulating the miR-204-5p/MYH9 axis in gastric cancer under hypoxia

2020 ◽  
Vol 40 (6) ◽  
Author(s):  
Xinhui Fang ◽  
Yangqiu Bai ◽  
Lida Zhang ◽  
Songze Ding
Keyword(s):  
Gastric Cancer ◽  
Lactate Production ◽  
Xenograft Model ◽  
Glucose Consumption ◽  
Luciferase Reporter ◽  
Migration And Invasion ◽  
Glucose Assay

Abstract Background: Gastric cancer (GC) is a malignant tumor of the digestive tract. Hypoxia plays an important role in the development of cancer, including GC. The present study aimed to investigate the role of circular RNA SLAMF6 (circSLAMF6) in the progression of GC under hypoxia. Methods: The expression of circSLAMF6, microRNA-204-5p (miR-204-5p) and myosin heavy chain 9 (MYH9) was measured by quantitative real-time polymerase chain reaction (qRT-PCR). GC cells were maintained under hypoxia (1% O2) for experiments in vitro. Glucose consumption and lactate production were determined by a Glucose Assay Kit and a Lactate Assay Kit, respectively. Levels of all protein were detected by Western blot. Cell migration and invasion were examined by Transwell assay. The interaction between miR-204-5p and circSLAMF6 or MYH9 was analyzed by dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. Murine xenograft model was established to explore the role of circSLAMF6 in vivo. Results: CircSLAMF6 expression was increased in GC cells under hypoxia. Hypoxia promoted glycolysis, migration, and invasion in GC cells, which were reversed by circSLAMF6 knockdown. CircSLAMF6 was validated as a miR-204-5p sponge, and MYH9 was a target of miR-204-5p. Functionally, miR-204-5p inhibitor weakened the inhibition of circSLAMF6 knockdown on GC cell progression under hypoxia. Besides, MYH9 depletion suppressed glycolysis, migration, and invasion in GC cells under hypoxia. Importantly, circSLAMF6 deficiency inhibited tumor growth in vivo by regulating the miR-204-5p/MYH9 axis. Conclusion: CircSLAMF6 was involved in glycolysis, migration, and invasion by regulating the miR-204-5p/MYH9 axis in GC cells under hypoxia.

scholarly journals MiR-199b-5p Promotes Gastric Cancer Progression by Regulating HHIP Expression

2021 ◽  
Vol 11 ◽  
Author(s):  
Songda Chen ◽  
Huijie Wu ◽  
Lingyu Zhu ◽  
Mengjie Jiang ◽  
Shuli Wei ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Western Blot ◽  
Cancer Progression ◽  
Bioinformatics Analysis ◽  
Luciferase Reporter ◽  
Rt Pcr ◽  
Mesenchymal Transition

ObjectivesGastric cancer (GC) is one of the most common malignant tumors. More and more evidences support the role of microRNAs (miRNAs) in tumor progression. However, the role of miRNAs in human GC remains largely unknown.MethodsBased on the published gastric cancer expression profile data, combined with bioinformatics analysis, potential miRNAs in the process of GC were screened. The expression of miR-199b-5p in GC cells and patients’ plasma was detected by RT-PCR. The effects of miR-199b-5p on GC in vitro were detected by EdU proliferation assay, colony formation assay, Transwell assay and wound healing assay. Western blot was used to detect epithelial-mesenchymal transition (EMT) related proteins. The subcutaneous tumorigenesis model and metastatic tumor model of mice were used to study its effect in vivo. Bioinformatics and Dual luciferase reporter assay were used to verify the effect of miR-199b-5p and its target gene.ResultsThrough bioinformatics analysis, we screened a novel miRNA miR-199b-5p that was significantly up-regulated in GC tissue and associated with poor prognosis of GC patients. RT-PCR results showed that its expression was also up-regulated in GC cell lines and patients’ plasma. MiR-199b-5p can significantly promote GC cell proliferation and migration in vitro and in vivo. Western blot showed that miR-199b-5p could promote the EMT process of GC. HHIP has been proved to be a target of miR-199b-5p, and the recovery of HHIP can weaken the effect of miR-199b-5p.ConclusionMiR-199b-5p may play an oncogene role in GC by targeting HHIP, suggesting that miR-199b-5p may be a potential therapeutic target for GC.

scholarly journals CircRNA-DOPEY2 Enhances The Chemosensitivity of Esophageal Cancer Cells By Inhibiting CPEB4-Mediated Mcl-1 Translation

2021 ◽  
Author(s):  
Zhenchuan Liu ◽  
Shaorui Gu ◽  
Kaiqin Wu ◽  
Lei Li ◽  
Chenglai Dong ◽  
...  
Keyword(s):  
Cancer Progression ◽  
Cisplatin Resistance ◽  
Critical Role ◽  
Major Barrier ◽  
Downstream Target ◽  
Element Binding Protein ◽  
Cisplatin Sensitivity

Abstract Background: Cisplatin-based chemotherapy is a mainstay systematic therapy for advanced esophageal squamous cell carcinoma (ESCC), and cisplatin resistance is not uncommon and the major barrier to patient outcome improvements. circRNAs are novel noncoding RNAs that are implicated in cancer progression, but their involvement in modulating cisplatin responsiveness in ESCC remains unknown. Methods: Bioinformatics analysis was used to profile and identify the circRNAs involved in cisplatin responsiveness in ESCC. The chemo-sensitive role of cDOPEY2was confirmed both in vitro and in vivo. The molecular mechanism of cDOPEY2 was investigated by mass spectrum, immunoprecipitation and ubiquitination analyses.Results: We report that a novel circRNA (cDOPYE2, hsa_circ_0008078) was markedly downregulated in cisplatin-resistant ESCC cells (ESCC-CR) compared with parental chemosensitive cells. Re-expression of cDOPEY2 substantially enhanced the cell-killing ability of cisplatin by augmenting the apoptotic process in ESCC-GR cells, which was achieved by decreasing the abundance of the antiapoptotic protein Mcl-1. Mechanistically, we showed that cDOPEY2 acted as a protein scaffold to enhance the interaction between the cytoplasmic polyadenylation element binding protein (CPEB4) and the E3 ligase TRIM25, which in turn facilitated the ubiquitination and degradation of CPEB4. The increased Mcl-1 expression in ESCC-GR cells was dependent on the binding of CPEB4 to its untranslated mRNA, and depletion of CPEB4 mediated by cDOPEY2 reversed this effect. Rescue experiments confirmed that the critical role of cDOPEY2 in maintaining cisplatin sensitivity was dependent on the depletion of CEPB4 and its downstream target Mcl-1. Clinical and in vivo data further corroborated the significant relevance of cDOPEY2 to cisplatin responsiveness in ESCC. Conclusions: We provide evidence that cDOPEY2 inhibits CPEB4-mediated Mcl-1 translation by promoting the ubiquitination and degradation of CPEB4 to alleviate cisplatin resistance, indicating that cDOPEY2 may serve as a valuable biomarker and potential therapeutic target in ESCC.

Sign in / Sign up

Export Citation Format

Share Document